DETROIT, OCT. 1 -- They finished the dress rehearsals in the American League East tonight, with the Baltimore Orioles presenting the Detroit Tigers a going-away gift, a 9-5 victory before 19,749 at Tiger Stadium.

In a season when they've done some incredible things, the Orioles always seem trying to go one better, and they got close tonight, committing three errors that allowed Detroit to score five unearned runs in the first two innings.

That got the Tigers (95-64) started to their 95th victory and closed them to within one game of the first-place Toronto Blue Jays (96-63) with three to play. The two teams will now decide the division championship this weekend, with the first of three scheduled games Friday night. Doyle Alexander (8-0) pitches against Jim Clancy (15-10) in that one.

The formula for both teams is this: The Blue Jays can win the division outright by taking two of the three games. The Tigers can win the division outright only by sweeping the series. If they win two of three, the championship will be decided in a Monday playoff in Detroit.

"This is it," Tigers Manager Sparky Anderson said. "No more bull. The fans are going to see good baseball from two good teams."

In the wrapup before the wrapup, starter Walt Terrell (17-10) survived a rough start, but went the distance for his 10th complete game. The Orioles got eight hits off him, including home runs by Ray Knight and Mike Young.

The Tigers had 11 hits, with shortstop Alan Trammell getting three and Matt Nokes and Kirk Gibson homering.

Meanwhile, Orioles starter Mike Boddicker (10-12) finished the season with more questions than answers. Still the closest to a staff ace the Orioles have, Boddicker allowed seven hits and two earned runs in 4 1/3 innings and ended the season with his second losing record in the last three.

It would be hard to measure his performance tonight because after Pete Stanicek, Cal Ripken Jr. and Terry Kennedy made errors that let in five runs, the Orioles were pretty much out of the game.

"I really can't say anything," Boddicker said. "I was up with the flu last night and didn't have good stuff. But you can't give teams four or five outs in an inning and expect to win."

One thing the Orioles (66-93) continue to do well is get thrown out of games. Outfielder Jim Dwyer was ejected in the seventh inning for arguing a strike call by umpire John Hirschbeck, then Manager Cal Ripken Sr. got it in the seventh for arguing a call at first by Durwood Merrill.

Those were the Orioles' 12th and 13th ejections of the year. After his, Ripken remained on the field five minutes to argue with Merrill, who also threw him out Monday night. At one point, he bumped the umpire.

Is Ripken frustrated? Tonight was his eighth ejection of the season, his fourth in the last 15 games.

"He threw me out because I said {an obscenity}," Ripken Sr. said. "There again, it's a case of me not being able to go on the field. Everytime I go on the field, I get run out of the game."

The Orioles took a brief lead, 2-0, in the first, when Terrell walked Dwyer and Fred Lynn, and Cal Ripken Jr. doubled them both in.

But in the bottom of the first, the Tigers scored four unearned runs. It started when Stanicek dropped a Bill Madlock pop-up. Trammell and Darrell Evans each singled to right. Madlock scored as Kennedy applied the tag and the ball popped out of his glove for the second error of the inning. It rolled away, and Trammell sprinted home with the tying run. Scott Lusader later singled to center for two more runs and a 4-2 lead. Ripken dropped a pop fly in the second inning that led to a fifth run.

In other games, Al Nipper, four for four against the Yankees this season, pitched a five-hitter and the visiting Boston Red Sox rallied for three runs in the eighth inning to beat New York, 7-5; rookie Jack McDowell won his third consecutive game as the White Sox won their seventh straight, 6-3, over the California Angels in Chicago; Mickey Brantley's three-run homer helped the Seattle Mariners beat the Rangers, 8-6, in Arlington, Tex., and, in Oakland, the Athletics closed their home season with a 9-5 victory over the Cleveland Indians.